updated jamfile to build on cygwin
updated jamfile to build on cygwin

hamedramzi/libtorrent,TeoTwawki/libtorrent,hamedramzi/libtorrent,TeoTwawki/libtorrent,TeoTwawki/libtorrent,snowyu/libtorrent,TeoTwawki/libtorrent,TeoTwawki/libtorrent,snowyu/libtorrent,snowyu/libtorrent,snowyu/libtorrent,hamedramzi/libtorrent,hamedramzi/libtorrent,snowyu/libtorrent,hamedramzi/libtorrent,TeoTwawki/libtorrent,hamedramzi/libtorrent,snowyu/libtorrent